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What is an intuitive explanation of the Expectation Maximization technique? [closed]
...behind this answer can be found here.
Suppose we have some data sampled from two different groups, red and blue:
Here, we can see which data point belongs to the red or blue group. This makes it easy to find the parameters that characterise each group. For example, the mean of the red group is...
Python Infinity - Any caveats?
...
You can still get not-a-number (NaN) values from simple arithmetic involving inf:
>>> 0 * float("inf")
nan
Note that you will normally not get an inf value through usual arithmetic calculations:
>>> 2.0**2
4.0
>>> _**2
16.0
>>> _...
How can I create a copy of an Oracle table without copying the data?
...
Just use a where clause that won't select any rows:
create table xyz_new as select * from xyz where 1=0;
Limitations
The following things will not be copied to the new table:
sequences
triggers
indexes
some constraints may not be copied
materialized view...
math.h 函数说明一览 - C/C++ - 清泛网 - 专注C/C++及内核技术
...数说明acos()求反余弦的值cos()求余弦值cosh()求双曲余玄值exp()e的次幂函数(以e为底的x次方值)frexp()把一个浮点数分解为尾数和指数ldex...
函数
说明
acos()
求反余弦的值
cos()
求余弦值
cosh()
求双曲...
How to select rows from a DataFrame based on column values?
How to select rows from a DataFrame based on values in some column in Pandas?
10 Answers
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python plot normal distribution
...could come up with is:
import numpy as np
import matplotlib.pyplot as plt
from scipy.stats import norm
# Plot between -10 and 10 with .001 steps.
x_axis = np.arange(-10, 10, 0.001)
# Mean = 0, SD = 2.
plt.plot(x_axis, norm.pdf(x_axis,0,2))
plt.show()
Sources:
http://www.johndcook.com/distribut...
What is the maximum float in Python?
...
It seems sys.float_info is available starting from v2.6. How about v2.3-5?
– Aleksei Fedotov
Jan 23 '15 at 13:40
1
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How to pass password to scp?
...com:/some/remote/path /some/local/path
The above copies contents of path from the remote host to your local.
Install :
ubuntu/debian
apt install sshpass
centos/fedora
yum install sshpass
mac w/ macports
port install sshpass
mac w/ brew
brew install https://raw.githubusercontent.com/...
Format bytes to kilobytes, megabytes, gigabytes
...
return round($bytes, $precision) . ' ' . $units[$pow];
}
(Taken from php.net, there are many other examples there, but I like this one best :-)
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Assigning a variable NaN in python without numpy
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Yes -- use math.nan.
>>> from math import nan
>>> print(nan)
nan
>>> print(nan + 2)
nan
>>> nan == nan
False
>>> import math
>>> math.isnan(nan)
True
Before Python 3.5, one could use float("nan") (case i...